These 3 energy storage technologies can help solve the challenge of moving to 100% renewable electricity

Energy storage can make facilities like this solar farm in Oxford, Maine, more profitable by letting them store power for cloudy days.
AP Photo/Robert F. Bukaty

Kerry Rippy, National Renewable Energy LaboratoryIn recent decades the cost of wind and solar power generation has dropped dramatically. This is one reason that the U.S. Department of Energy projects that renewable energy will be the fastest-growing U.S. energy source through 2050.

However, it’s still relatively expensive to store energy. And since renewable energy generation isn’t available all the time – it happens when the wind blows or the sun shines – storage is essential.

As a researcher at the National Renewable Energy Laboratory, I work with the federal government and private industry to develop renewable energy storage technologies. In a recent report, researchers at NREL estimated that the potential exists to increase U.S. renewable energy storage capacity by as much as 3,000% percent by 2050.

Here are three emerging technologies that could help make this happen.

Longer charges

From alkaline batteries for small electronics to lithium-ion batteries for cars and laptops, most people already use batteries in many aspects of their daily lives. But there is still lots of room for growth.

For example, high-capacity batteries with long discharge times – up to 10 hours – could be valuable for storing solar power at night or increasing the range of electric vehicles. Right now there are very few such batteries in use. However, according to recent projections, upwards of 100 gigawatts’ worth of these batteries will likely be installed by 2050. For comparison, that’s 50 times the generating capacity of Hoover Dam. This could have a major impact on the viability of renewable energy.

Batteries work by creating a chemical reaction that produces a flow of electrical current.

One of the biggest obstacles is limited supplies of lithium and cobalt, which currently are essential for making lightweight, powerful batteries. According to some estimates, around 10% of the world’s lithium and nearly all of the world’s cobalt reserves will be depleted by 2050.

Furthermore, nearly 70% of the world’s cobalt is mined in the Congo, under conditions that have long been documented as inhumane.

Scientists are working to develop techniques for recycling lithium and cobalt batteries, and to design batteries based on other materials. Tesla plans to produce cobalt-free batteries within the next few years. Others aim to replace lithium with sodium, which has properties very similar to lithium’s but is much more abundant.

Safer batteries

Another priority is to make batteries safer. One area for improvement is electrolytes – the medium, often liquid, that allows an electric charge to flow from the battery’s anode, or negative terminal, to the cathode, or positive terminal.

When a battery is in use, charged particles in the electrolyte move around to balance out the charge of the electricity flowing out of the battery. Electrolytes often contain flammable materials. If they leak, the battery can overheat and catch fire or melt.

Scientists are developing solid electrolytes, which would make batteries more robust. It is much harder for particles to move around through solids than through liquids, but encouraging lab-scale results suggest that these batteries could be ready for use in electric vehicles in the coming years, with target dates for commercialization as early as 2026.

While solid-state batteries would be well suited for consumer electronics and electric vehicles, for large-scale energy storage, scientists are pursuing all-liquid designs called flow batteries.

A typical flow battery consists of two tanks of liquids that are pumped past a membrane held between two electrodes.
Qi and Koenig, 2017, CC BY

In these devices both the electrolyte and the electrodes are liquids. This allows for super-fast charging and makes it easy to make really big batteries. Currently these systems are very expensive, but research continues to bring down the price.

Storing sunlight as heat

Other renewable energy storage solutions cost less than batteries in some cases. For example, concentrated solar power plants use mirrors to concentrate sunlight, which heats up hundreds or thousands of tons of salt until it melts. This molten salt then is used to drive an electric generator, much as coal or nuclear power is used to heat steam and drive a generator in traditional plants.

These heated materials can also be stored to produce electricity when it is cloudy, or even at night. This approach allows concentrated solar power to work around the clock.

Checking a molten salt valve for corrosion at Sandia’s Molten Salt Test Loop.
Randy Montoya, Sandia Labs/Flickr, CC BY-NC-ND

This idea could be adapted for use with nonsolar power generation technologies. For example, electricity made with wind power could be used to heat salt for use later when it isn’t windy.

Concentrating solar power is still relatively expensive. To compete with other forms of energy generation and storage, it needs to become more efficient. One way to achieve this is to increase the temperature the salt is heated to, enabling more efficient electricity production. Unfortunately, the salts currently in use aren’t stable at high temperatures. Researchers are working to develop new salts or other materials that can withstand temperatures as high as 1,300 degrees Fahrenheit (705 C).

One leading idea for how to reach higher temperature involves heating up sand instead of salt, which can withstand the higher temperature. The sand would then be moved with conveyor belts from the heating point to storage. The Department of Energy recently announced funding for a pilot concentrated solar power plant based on this concept.

Advanced renewable fuels

Batteries are useful for short-term energy storage, and concentrated solar power plants could help stabilize the electric grid. However, utilities also need to store a lot of energy for indefinite amounts of time. This is a role for renewable fuels like hydrogen and ammonia. Utilities would store energy in these fuels by producing them with surplus power, when wind turbines and solar panels are generating more electricity than the utilities’ customers need.

Hydrogen and ammonia contain more energy per pound than batteries, so they work where batteries don’t. For example, they could be used for shipping heavy loads and running heavy equipment, and for rocket fuel.

Today these fuels are mostly made from natural gas or other nonrenewable fossil fuels via extremely inefficient reactions. While we think of it as a green fuel, most hydrogen gas today is made from natural gas.

Scientists are looking for ways to produce hydrogen and other fuels using renewable electricity. For example, it is possible to make hydrogen fuel by splitting water molecules using electricity. The key challenge is optimizing the process to make it efficient and economical. The potential payoff is enormous: inexhaustible, completely renewable energy.

[Understand new developments in science, health and technology, each week. Subscribe to The Conversation’s science newsletter.]

Kerry Rippy, Researcher, National Renewable Energy Laboratory

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Enjoy them while you can? The ecotourism challenge facing Australia’s favourite islands

Remarkable Rocks, Kangaroo Island, South Australia.
Greg Brave/Shutterstock

Freya Higgins-Desbiolles, University of South Australia

I fell for Kangaroo Island from my first visit. I recall standing on a headland on the island’s southern coast, near Remarkable Rocks (a popular tourist site), and being awestruck by the Southern Ocean.

The island (Australia’s third-largest after Tasmania and Melville Island) is one of 16 designated National Landscapes and arguably South Australia’s greatest tourism treasure. Its protected areas (notably Flinders Chase National Park) are home to rare and endangered marsupials and birds.

A year ago, in Australia’s “Black Summer”, bushfires ravaged more than half the island (about 211,000 hectares). Those fires underscored the threat to this and other iconic island destinations.

Both directly and indirectly, humans are endangering these fragile ecosystems through unsustainable development and human-caused climate change.

The most ironic threat is from unsustainable tourism. These islands attract millions of visitors a year keen to experience their natural wonders. Yet often this very “ecotourism” is contributing to their degradation.

How to do better?

Last October I took part in a workshop at which Kangaroo Island’s tourism operators discussed how to do so. 2020 was a difficult year for them, first with the fires, then with the COVID-19 pandemic. But in that adversity they also saw the opportunity to reset “business as usual” and come back better, creating an industry not harming its core asset.

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The end of global travel as we know it: an opportunity for sustainable tourism

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A range of ideas came out of our talks applicable to all our island destinations. But there was one key point. Ecotourism should be more than fleeting feel-good experiences. It should not be a “value extraction” but a “values education”, inspiring visitors to go home and live more eco-consciously.

Macquarie island

The paradox of ecotourism is perhaps best exemplified by Australia’s least visited island destination – Macquarie Island, about 1,500 km south-east of Hobart, halfway between New Zealand and the Antarctica.

Just 1,500 tourists a year, rather than hundreds of thousands, are permitted by the Tasmania Parks and Wildlife Service to visit. The island has no hotels, restaurants or souvenir shops. The only buildings are those of the Macquarie Island Station research base and a few isolated field huts for scientists.

The Macquarie Island Research Base.
Dale Lorna Jacobsen/Shutterstock

Tourists must be content with coming ashore for the day from the 18 small cruise ships that ply these waters in summer. The only hospitality is the traditional station offering of tea and scones.

But what tourists do get is a unique experience. Macquarie is World Heritage listed as the only island made entirely from the earth’s mantle. It also teems with wildlife – multiple species of penguins and seals in their tens of thousands, and birds in their millions.

Royal Penguins and Southern Elephant Seals at Sandy Bay, Macquarie Island.
Janelle Lugge/Shutterstock

It’s about as pure an ecotourism experience you can have (if you can afford it). Even so, it still takes resources to get there, including the burning of fossil fuels, contributing to the global warming that is the greatest threat to the environmental integrity of Macquarie Island (and other island ecosystems).

However, the Tasmania Parks and Wildlife Service does at least expect cruise ship operators to “demonstrate their capacity to deliver desirable outcomes” on criteria including minimisation of environmental impacts and communicating to tourists “messages about the natural and cultural values of the island”, including the role they play in its preservation.

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This could be the end of the line for cruise ships

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K’gari (Fraser island)

Communicating such messages is something that certainly needs improvement on another World Heritage listed island – K’gari (commonly known as Fraser island), the world’s largest sand island.

About 250 km north of Brisbane, at the southern end of the Great Barrier Reef, the island draws many hundreds of thousands of visitors a year to its beaches, woodlands and rainforests. (There are no recent public statistics on island visitor numbers but in 2017-18 the Fraser Coast region attracted 1,515,000 visitors.)

Rainforest on K’gari.
Marco Saracco/Shutterstock

Once the island’s resources were mined and logged. Tourism was meant to be much less exploitative. But a range of organisations including the International Union for Conservation of Nature have highlighted the pressure tourist numbers (along with their vehicles and infrastructure) are placing on K’gari’s landscapes and wildlife.

Communicating to all those visitors the role they play in the island’s preservation appears to be failing. The bushfires that burnt half the island (about 165,500 hectares) over nine weeks between October and December last year allegedly resulted from an illegal camp fire.

Headline-grabbing attacks by the island’s residents dingos – such as in April 2019 when a toddler was dragged from a campervan – have also been credited to rampant irresponsible tourist behaviour (feeding dingoes to get better photos, for example).

Indigenous elders, conservationists and scientists have all pointed to the problem of a mass-tourism model that doesn’t put enough emphasis on educating visitors about the environment and their responsibilities.

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Read more:
The K’gari-Fraser Island bushfire is causing catastrophic damage. What can we expect when it’s all over?

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Rottnest Island

One of our proposals for Kangaroo Island is to reduce the impact of motor vehicles through encouraging more extended walking and cycling experiences.

The value of sustainable transport as the foundation for ecotourism is demonstrated by Rottnest Island, 20 km off the coast of Perth.

The entire island is managed as an A-Class Nature Reserve. Apart from service vehicles and shuttle buses, it is car-free. You can hire a bike or bring your own to get around the island (11 km long and 4.5 km wide). Or simply walk.

The absence of traffic makes a Rottnest holiday a distinctly more relaxed experience. It’s a fair example of slow tourism; and, of course, it is also good for the island’s world famous quokkas, which co-exist with close to 800,000 visitors a year.

Rottnest island has the world’s only sizeable population of quokkas. There are 10,000 to 12,000 quokkas on the island.
Grakhantsev Nikolai/Shutterstock

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Before and after: 4 new graphics show the recovery from last summer’s bushfire devastation

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Before they are gone

Given a little space, nature is resilient.

After Kangaroo Island’s bushfires a year ago, for example, it was feared a number of endangered species had finally been driven to extinction.

But in two of 2020’s few good news stories, scientists found critically endangered Kangaroo Island dunnarts and little pygmy possums – the world’s smallest marsupial – had survived.

Kangaroo Island pygmy possum.
Ashlee Benc/Kangaroo Island Land for Wildlife, CC BY

But we can’t take that resilience for granted if we keep putting pressure on these fragile ecosystems. We need a better approach to ensure ecotourism isn’t about enjoying these natural wonders before they are gone.

Freya Higgins-Desbiolles, Senior Lecturer in Tourism Management, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Massive road and rail projects could be Africa’s greatest environmental challenge

Bill Laurance, James Cook University

Africa’s natural environments and spectacular wildlife are about to face their biggest challenge ever. In a paper published today in Current Biology, my colleagues and I assess the dramatic environmental changes that will be driven by an infrastructure-expansion scheme so sweeping in scope, it is dwarfing anything the Earth’s biggest continent has ever been forced to endure.

People, food and mining

Africa’s population is exploding – expected nearly to quadruple this century, according to the United Nations. With that, comes an escalating need to improve food production and food security.

In addition, Africa today is experiencing a frenzy of mining activity, with most of the investment coming from overseas. China, for instance, is investing over US$100 billion annually, with India, Brazil, Canada and Australia also being big foreign investors.

To feed its growing population and move its minerals to shipping ports for export, Africa needs better roads and railroads. When located in the right places, improved transportation can do a lot of good. It makes it easier for farmers to get access to fertiliser and new farming technologies, and cheaper to get crops to urban markets with less spoilage. It can also encourage rural investment while improving livelihoods, access to health services, and education for local residents.

Improved transportation is especially important for Africa’s agriculture, which is badly under-performing. In many areas, large “yield gaps” exist between what could be produced under ideal conditions and what is actually being produced. With better farming, Africa’s yields could be doubled or even tripled without clearing one more hectare of land.

Using rudimentary methods, small-scale farmers eke out a living in Gabon.
William Laurance

Pandora’s box

However, there is another side to new transportation projects — a dark side, especially for the environment. When located in areas with high environmental values, new roads or railroads can open a Pandora’s box of problems.

Roads slicing into remote areas can lead to range of legal and illegal human land uses. For instance, in the Amazon, 95% of all deforestation occurs within five kilometres of a road; and for every kilometre of legal road there are three kilometres of illegal roads. In the Congo Basin, forest elephants decline sharply, and signs of hunters and poachers increase, up to 50 kilometres from roads.

A forest elephant shot by poachers.
Ralph Buij

In the wrong places, roads can facilitate invasions of natural areas by illegal miners, colonists, loggers and land speculators. In my view, the explosive expansion of roads today is probably the greatest single peril to the world’s natural environments and wildlife.

Africa’s ‘development corridors’

Earlier studies that my colleagues and I conducted, including a major study published in Nature last year, suggest Africa is likely to be a global epicentre of environmental conflict. A key reason: an unprecedented scheme to dramatically expand African roads, railroads and energy infrastructure.

In total, we have identified 33 massive “development corridors” that are being proposed or are underway. At the heart of each corridor is a road or railroad, sometimes accompanied by a pipeline or power line.

The 33 development corridors that are being proposed or constructed in sub-Saharan Afirca.
William F. Laurance et al. (2015) Current Biology.

The projects have a variety of proponents, including the African Development Bank, national governments, international donors and lenders, and commercial agricultural and mining interests. They’re intended to promote large-scale development and their scope is breathtaking.

If completed in their entirety, the corridors will total over 53,000 kilometres in length, crisscrossing the African continent. Some individual corridors are over 4,000 kilometres long.

Will these corridors generate key social and economic benefits, or will they cause great environmental harm? To address this question, we looked at three factors, focusing on a 50-kilometre-wide band laid over the top of each corridor.

First, we assessed the “natural values” of each corridor, by combining data on its biodiversity, endangered species, critical habitats for wildlife, and the carbon storage and climate-regulating benefits of its native vegetation.

Second, we mapped human populations near each corridor, using satellite data to detect nightlights from human settlements (to avoid lands that were simply being burned, we included only places with “persistent” nightlights). We then combined the natural-value and population data to generate a conservation-value score for each corridor, reasoning that sparsely populated areas with high natural values have the greatest overall conservation value.

Finally, we estimated the potential for new roads or railroads to increase food production. Areas that scored highly had soils and climates suitable for farming but large yield gaps, were within several hours’ drive of a city or port, and were projected to see large future increases in food demand.

Costs versus benefits

When we compared the conservation value of each corridor with its potential agricultural benefits, we found huge variation among the corridors.

A two-minute video summary of our study’s main findings

A half dozen of the corridors look like a really good idea, with large benefits and limited environmental costs. However, another half dozen seem like a really bad idea, in that they’d damage critical environments, especially rainforests of the Congo Basin and West Africa and biologically rich equatorial savanna regions.

In the middle, there are 20 or so corridors that appear “marginal”. These tend to have high environmental values and high potential agricultural benefits, or vice versa.

We argue that these marginal projects should be evaluated in detail, on a case-by-case basis. If they do proceed, it should only happen under the most stringent conditions, with careful environmental assessment and land-use planning, and with specific measures in place (such as new protected areas) to limit or mitigate their impacts.

Dangers for Africa

There’s no such thing as a free ride. For Africa, the dangers of the development corridors are profound. Even if well executed, we estimate that the current avalanche of corridors would slice through over 400 protected areas and could easily degrade another 2,000 or so. This bodes poorly for Africa’s wildlife and biodiversity generally.

Wild zebras in the Serengeti.
William Laurance

Beyond this, the corridors will encourage human migration into many sparsely populated areas with high environmental values. The wild card in all this is the hundreds of billions of dollars of foreign investments pouring into Africa each year for mining. Even if a corridor is likely to yield only modest benefits for food production, it may be very difficult for governments and decision makers to say no to big mining investors.

The bottom line: it could be a fraught battle to stop even ill-advised development corridors, though not impossible. If we shine a bright light on the corridors and argue strongly that those with limited benefits and large costs are a bad idea, we may succeed in stopping or at least delaying some of the worst of them.

This is unquestionably a vital endeavour. Africa is changing faster than any continent has ever changed in human history, and it is facing unprecedented socioeconomic and environmental challenges.

The next few decades will be crucial. We could promote relatively sustainable and equitable development — or end up with an impoverished continent whose iconic natural values and wildlife have been irretrievably lost.

Bill Laurance, Distinguished Research Professor and Australian Laureate, James Cook University

This article was originally published on The Conversation. Read the original article.

Video: Acid Test – The Global Challenge of Ocean Acidification

Video: The Island President

The link below is to an article on the film ‘The Island President,’ which deals with the challenge of Climate Change and the Maldive Islands.

For more visit:
http://grist.org/climate-change/triumph-tragedy-and-climate-change-the-island-president/

THE ISLAND PRESIDENT—A Documentary By Jon Shenk | Official Trailer from Sawyer Studios on Vimeo.